DETROIT — A truck driver has been charged in federal court with threatening to assassinate President Donald Trump in several phone calls to Secret Service field offices.

Special Agent Matthew Lariviere wrote in a criminal complaint unsealed Tuesday that James Anthony Jackson repeatedly called the Secret Service field office in Chicago on Oct. 12-13 and made more phone calls to the field office in Detroit on Oct. 18 threatening to “blow Trump’s brains out.”

Lariviere wrote Jackson called from a phone that was registered to James Jackson Profit Group LLC in Grand Rapids, Michigan. The Detroit News reports the company is linked to an outreach centre in Grand Rapids.

The News reports Jackson was born in 1984 but a hometown wasn’t available and the U.S. Attorney’s Office refused to discuss the case.